I think these are good suggestions. I had to do aesthetic maintenance on those apps I manage where the top border is white. Branding icons we use sitting against a purple background does not look so good.
As Matt suggested, put your branding at the bottom to be less conspicuous. There's really no valid reason for the glaring QB branding in apps that we're paying for. Let us paying users brand our QB apps to reflect our business to our customers.
We really do hope Quick Base will reconsider locking us into a purple themed interface and allow us to customize the styles.